It is known that certain therapeutic treatments comprise the application of cold masses or of hot masses to the parts of the body to be treated. As an example of cold therapy, the treatment of contusions or of operative incisions may be cited. Used for that purpose are cold pads which warm up gradually starting from a temperature of about 0.degree. C. up to body temperature. The materials used, e.g., mixtures of water and glycol, release the kilocalories which they have stored according to a constant-elevation process, thus in a linear manner. In order for their cooling effect to last long enough, it is therefore necessary that they be highly cooled. However, the application of very low-temperature bodies to the skin may be disagreeable and even bring about local frostbite. Added to this is that the efficiency of the application of these methods from the point of view of the desired therapeutic effect is far from being optimal.
Thus, most of the known cooling pads currently on the market have drawbacks. As indicated above, they rapidly lose their effect, so that they must be changed frequently, which brings about temperature variations unfavorable for the therapy aimed at and requires a considerable commitment from the nursing personnel. Certain known cooling pads, such as that described in German patent DE 31 41 191, for example, have the drawback that the thermally active material does not occupy the whole of the volume of the pad since it forms an emulsion with a non-active emulsifier, which reduces its effectiveness.
In order partially to remedy these drawbacks, and especially the rapid variation of the temperature of the cold pads upon contact with the body, it has already been contemplated to use ice cubes, which have the advantage of remaining at the temperature of 0.degree. C. as long as they have not entirely melted. The ice can indeed absorb from the body with which it is in contact an amount of heat equal to its latent heat of fusion, which is 314 KJ/kg. In melting, however, the blocks of ice wet the articles of clothing with which they are in contact, and moreover, in the solid state, they generally have sharp edges which can injure the skin.
Likewise known, in particular from U.S. Pat. No. 4,527,566, are flexible bandages equipped with pockets capable of receiving blocks of ice or hot cells, but this bandage remedies the above-mentioned drawbacks only partially.
The French patent FR 1,365,666 also contains a description of a packaging for masses of a freezable liquid. These masses are enclosed in recipients which are themselves placed in packages of diverse shapes and constructions.